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21.
Rajiv Prakash 《应用聚合物科学杂志》2002,83(2):378-385
Polyaniline was electrochemically synthesized from an aqueous medium with various acid electrolytes via potentiodynamic and potentiostatic techniques. The electrochemical synthesis of polyaniline was studied over various substrates, including Pt, Ti, Ni, and SnO2 coated glass, and in various acid electrolytes. Cyclic voltammograms of electrochemically synthesized polyaniline were studied in HCl in a pH range of 1–4. Probable electrochemistry and chemical changes were deduced that occurred when polyaniline film was electrochemically oxidized and reduced between ?0.2 and 1.0 V versus a Ag/AgCl reference electrode in an acidic electrolyte at pH 1, and three corresponding oxidation and reduction peaks were described instead of two redox peaks (as observed by W. S. Huang, B. D. Humphrey, and A. G. MacDiarmid, J Chem Soc Faraday Trans 1 1986, 82, 2385). The electrochromic property was studied with changes in the chemical states of polyaniline during electrochemical oxidation and reduction. A new viscous electrolyte, aqueous AlCl3 (pH 2), saturated with AgCl was used for the construction of an electrochromic display device. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 378–385, 2002 相似文献
22.
23.
Cocaine abuse today has reached greater heights than it did during the first cocaine epidemic in the late nineteenth century. It is estimated that one out of every four Americans has used cocaine and some six million people in the US use it regularly. Although cocaine affects all systems in the body, the central nervous system (CNS) is the primary target. Cocaine blocks the reuptake of neurotransmitters in the neuronal synapses. Almost all CNS effects of cocaine can be attributed to this mechanism. Euphoria, pharmacological pleasure and intense cocaine craving share basis in this system. The effects of cocaine on other organ systems, in addition to its effects on the CNS, account for the majority of the complications associated with cocaine abuse. In this paper, the CNS effects following cocaine administration and their treatment are discussed. 相似文献
24.
We have calculated thermal conductivity of alumina nanofluids (with water and ethylene glycol as base fluids) using temperature
as well as concentration-dependent viscosity, η. The temperature profile of η is obtained using Gaussian fit to the available experimental data. In the model, the interfacial resistance effects are incorporated
through a phenomenological parameter α. The micro-convection of the alumina nanoparticle (diameter less than 100 nm) is included through Reynolds and Prandtl numbers.
The model is further improved by explicitly incorporating the thermal conductivity of the nanolayer surrounding the nanoparticles.
Using this improved model, thermal conductivity of copper nanofluid is calculated. These calculations capture the particle
concentration-dependent thermal conductivity and predict the dependence of the thermal conductivity on the size of the nanoparticle.
These studies are significant to understand the underlying processes of heat transport in nanofluids and are crucial to design
superior coolants of next generation. 相似文献
25.
Changes in the NHS have supported the idea of targeting health services to those in greatest need. This has meant that health visitors are increasingly having to identify 'vulnerable' families in need of increased health visiting intervention. This paper reports on a qualitative study undertaken in order to explore the ways in which health visitors plan and organize their work in relation to the concept of vulnerability. Focus groups and semi-structured interviews were carried out with health visitors from two separate geographical areas, one an inner city area and the other suburban, in order to explore the criteria by which health visitors define vulnerability and decide to increase their levels of intervention to particular families. It was found that vulnerability was extremely difficult to define but that the health visitors used criteria which were appropriate to the particular localities in which they worked to identify vulnerable families and to increase their levels of intervention to those families. Health visitors were targeting their services within a framework of a basic minimum service to all and were assessing the health needs of individuals or families rather than planning their work on the basis of community or practice profiles. 相似文献
26.
Ti–TiN and TiN–CrN nanomultilayers were thermally stable retaining uniform and sharp layer interfaces up to 24 h at 773 K, without any oxidation or phase transformation accompanying each individual layer. Decreasing the multilayer spacing resulted in an increase in the hardness in both cases. The coating hardness was found to be independent of the substrate type, when applied on HS718, Ti64 and HCHCr substrates. In scratch testing, the multilayers displayed a better resistance to the onset of failure, as compared to the monolayer TiN. The substrate plasticity played an important role in determining the coating failure mode. Self-mated wear tests revealed the CrN–TiN system to exhibit the best wear behaviour, both at room temperature and at 773 K. The Ti–TiN coatings are more accommodative with all three substrates, as compared to TiN–CrN and TiN. 相似文献
27.
P Anand 《Canadian Metallurgical Quarterly》1998,352(9140):1629-1630
28.
JL Funderburgh ML Funderburgh MM Mann S Prakash GW Conrad 《Canadian Metallurgical Quarterly》1996,271(49):31431-31436
Keratan sulfate proteoglycans (KSPGs) are the major proteoglycans of the cornea and are secreted by keratocytes in the corneal stroma. Previous studies have been able to show only transient secretion of KSPG in cell culture. In this study, cultures of bovine keratocytes were found to secrete the three previously characterized KSPG proteins into culture medium. Reactivity with monoclonal antibody I22 demonstrated substitution of these proteins with keratan sulfate chains. KSPG constituted 15% of the proteoglycan metabolically labeled with [35S]sulfate in keratocyte culture medium. This labeled KSPG contained keratan sulfate chains of 4700 Da compared to 21,000 Da for bovine corneal keratan sulfate. Labeled keratan sulfate from cultures contained nonsulfated, monosulfated, and disulfated disaccharides that were released by digestion with endo-beta-galactosidase or keratanase II. Nonsulfated disaccharides were relatively more abundant in keratan sulfate from culture than in corneal keratan sulfate. These results show that cultured bovine keratocytes maintain the ability to express all three of the known KSPG proteins, modified with keratan sulfate chains and sulfated on both N-acetylglucosamine and galactose moieties. KSPG made in vitro differs from that found in vivo in the length and sulfation of its keratan sulfate chains. The availability of cell cultures secreting corneal keratan sulfate proteoglycans provides an opportunity to examine biosynthesis and control of this important class of molecules. 相似文献
29.
Towards an effective integration of cellular users to the structured Peer-to-Peer network 总被引:1,自引:1,他引:0
Mohammad Zulhasnine Changcheng Huang Anand Srinivasan 《Peer-to-Peer Networking and Applications》2012,5(2):178-192
Integration of cellular users into the peer-to-peer (P2P) network is still in limbo due to limitations caused by heterogeneity,
mobility and time-varying capacities of the wireless channel. If traditional Chord is employed to include users from the cellular
networks, users under the same base station scatter in logical topology randomly. In this paper, we present a novel cellular
Chord (C-Chord) P2P system that integrates the cellular users into the well-established structured P2P network in a topology-aware
fashion. C-Chord offers the cellular users a choice of downloading contents either from the Internet peers at a faster rate
or from other cellular users from the same base station avoiding the Internet data penalty. We also incorporate the peer selection
module based on stable marriage problem that chooses the appropriate candidate from the discovered potential senders. We conduct
extensive simulations to evaluate the performance of the proposed C-Chord P2P system and the peer selection module. Simulation
results show that the path-length per lookup query is smaller than that of the traditional Chord system. Overhead due to renewal
of routing information is also smaller for the cellular users in the C-Chord system. We also measure the throughput at the
cellular receivers to analyze the effects of selecting peers either from same base station or from outside the Internet gateway.
Throughput also increases dramatically due to an intelligent selection of peers among the potential senders. 相似文献
30.
Aman Singh Jaydip Chandrakant Mehta Divya Anand Pinku Nath Babita Pandey Aditya Khamparia 《Expert Systems》2021,38(1)
In real world, the automatic detection of liver disease is a challenging problem among medical practitioners. The intent of this work is to propose an intelligent hybrid approach for the diagnosis of hepatitis disease. The diagnosis is performed with the combination of k‐means clustering and improved ensemble‐driven learning. To avoid clinical experience and to reduce the evaluation time, ensemble learning is deployed, which constructs a set of hypotheses by using multiple learners to solve a liver disease problem. The performance analysis of the proposed integrated hybrid system is compared in terms of accuracy, true positive rate, precision, f‐measure, kappa statistic, mean absolute error, and root mean squared error. Simulation results showed that the enhanced k‐means clustering and improved ensemble learning with enhanced adaptive boosting, bagged decision tree, and J48 decision tree‐based intelligent hybrid approach achieved better prediction outcomes than other existing individual and integrated methods. 相似文献